Philip Morris, the largest cigarette producer in the United States, said net income in the latest three months rose to $371 million, or $1.56 a share, from $283 million, or $1.19 a share, in the corresponding 1985 quarter. Operating revenues increased to $6.55 billion from $5.30 billion.

For the full year, Philip Morris said earnings increased 17.5 percent, to $1.48 billion, or $6.20 a share, from $1.26 billion, or $5.24 a share, in 1985. Revenues soared 59.2 percent, to $25.41 billion, from $15.96 billion. Gains by General Foods

The General Foods Corporation, which was acquired by Philip Morris in November 1985, showed, for the full year, an increase in operating income of 7.2 percent, to $740 million, with revenues rising to $9.7 billion.

The company said that full-year operating income from Miller Brewing rose 16.7 percent, to $158 million, on a 4.8 percent increase in operating revenue, to $3.1 billion. Miller's shipments for the year totaled 38.7 million barrels, a 4.4 percent increase over 1985 and the first significant gain in four years, the company said.

Results for 1986 exclude the Seven-Up Company. Philip Morris sold the international operations of Seven-Up to Pepsico Inc. last July; the American franchise business was sold to a group of investors in November.